The science behind the swimsuit war

Germany's Paul Biedermann edges out American Michael Phelps in the men's 200-meter freestyle final on Tuesday at the FINA World Swimming Championships in Rome. The outcome added to a yearlong controversy over swimsuits.

This month's crackdown on slick swimsuits marks a rare retreat in the technological arms race (and legs race) that has dominated international sports - but it doesn't mean the multimillion-dollar quest for a high-tech edge is over.

"We've already started to think about what kinds of things we'll be doing for 2012," said Rick Sharp, an exercise physiologist at Iowa State University who has played a key role in the swimsuit wars. Then he added with a chuckle, "I can't tell you what those are."

Sharp was part of an outside team of experts - also including NASA engineer Stephen Wilkinson - who helped Speedo develop its full-body LZR Racer ("laser racer") swimsuit for last year's Beijing Olympics. Swimmers wearing the bodysuit (including Olympic superstar Michael Phelps) broke records galore, and that led competitors to ask angrily whether using the suit amounted to "technological doping."

Swimsuit tech has been making headlines for almost 10 years, starting with the "Fastskin" suits introduced by Speedo for the 2000 Olympics. The idea was that the suits' V-shaped ridges, modeled after shark scales, would cut down on drag and let the swimmer slide faster through the water.

Sharp's specialty is testing the claims for improvements in sports performance. For instance, did shaving body hair have a measurable effect on a swimmer's performance? (Yes, it did.) OK, so did wearing that sharkskin suit have a measurable effect? (Um, no, not really.)

"Because of that work, yeah, Speedo came to me and asked me to help with research and development," Sharp told me on Tuesday.

With an assist from Sharp and his colleagues, Speedo tested a variety of drag-reducing designs and fabrics to come up with a suit that would have a measurable effect. "Basically, it's a matter of having a garment on that will reduce the water resistance as much as possible," Sharp explained.

Part of the challenge is the kind of material you use, and where you use it. The Speedo team came up with a design that put panels of polyurethane over parts of the body that produce the highest drag. Another part is the suit design: You don't want a suit that traps water as it flows around the swimmer. Yet another innovation is to use material that squeezes and slims down swimmers "so the skin doesn't wobble around as they go through the water," Sharp said.

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Click for video: After Michael Phelps' defeat, TODAY hosts talk to sports broadcaster Rowdy Gaines about whether his swimsuit played a part.

Pieces of fabric were put through wind-tunnel tests to check for drag. Programmers used computational fluid dynamics to model the suits' aerodynamic qualities, as if they were trying to figure out how a brand-new jet will fly. Then, swimmers put the designs to real-world tests in tanks and pools.

The results at the Beijing Olympics were jaw-dropping: Twenty-three world records were broken by the swimmers who wore LZR Racer suits, compared with only two that were broken by the swimmers who didn't. Speedo said 89 percent of all the medals in swimming (including 94 percent of the gold medals) were won by LZR Racer swimmers.

First came the complaints. Then came the escalation: Italian swimsuit makers Arena and Jaked both came out with suits that one-upped the Speedo by using pure polyurethane. "It was relatively obvious to some companies to say, 'Well, let's just make the whole suit out of this stuff,'" Sharp said.

World records once again started dropping like cannonballs off the high-dive. And that only deepened suspicions that pockets of air were somehow being trapped between the polyurethane and the swimmers' skin. If that were the case, the added buoyancy would give those swimmers an unfair advantage.

That's just the kind of issue scientists might be able to settle, but Sharp said he's not aware of any data on the buoyancy question. "This has only been around since about June, so there hasn't been any time for studies to be done," he told me.

He's pretty sure, however, that buoyancy wasn't as much of an issue with the Speedo suits. "We didn't make the whole suit out of polyurethane, we just used patches in a sense," he said. "Some of the new suits ... are completely impermeable to water."

Last week, the governing body for international swimming, known as FINA, decided to ban full-body suits and set stricter standards for their composition. Polyurethane is out. The suits will have to be made exclusively from textiles.

There's another catch, however: FINA's new rules won't go into effect until as late as next spring, which implies that the super-slick, Speedo-beating suits will continue to be worn and records will continue to be broken.

Tony Gentile / Reuters

Germany's Paul Biedermann celebrates in his Arena X-Glide bodysuit after setting a world record in the men's 200-meter freestyle.

On Tuesday, the situation came to a head when Michael Phelps (wearing a Speedo) came in second to Germany's Paul Biedermann (wearing an Arena X-Glide). The unexpected defeat led Phelps' coach to declare that the world's best-known swimmer probably won't swim in international competitions until the rules change.

"It has to be implemented immediately," coach Bob Bowman said of the polyurethane ban. "The sport is in shambles right now, and they better do something or they're going to lose their guy who fills these seats."

Sharp agreed that the next few months could get rocky. "It's going to be a free-for-all until then," he told me. But then what? Will it be 1999 all over again?

Sharp is certain that the swimwear manufacturers won't just dust off their old designs. "I know they're thinking and talking, and maybe hypothetically designing as we speak," he said.

Speedo has said developing the LZR Racer suit cost several million dollars, and there's no reason to think that kind of spending will stop just because the development effort has to go in a new direction. There's also no reason to think that the $550 price tag for an Olympic-ready swimsuit will be trimmed back as much as the bodysuit itself. You can bet that the shorter swimsuits dreamed up for the London Olympics in 2012 will be touted as the latest and the greatest, as well as street-legal.

The gears inside Sharp's head are already turning.

"I don't think we've exhausted all the possibilities in thread-based materials," he said. "They can still work more on fit, making sure something isn't scooping water and acting as a parachute as they go through the water. But all these things will be within limits, and I think that's progress."

FINA officials will likely be working along with swimsuit manufacturers to make sure the revised rules leave room for new high-tech twists.

"They don't want to stifle innovation completely, but at the same time they don't want to have equipment that enhances performance beyond what the swimmer's natural ability is," Sharp said. "We maybe won't 'enhance' their performance, but we can impair it less."

Then Sharp lets loose with that chuckle again. "You might call that spin doctoring," he said.